Wadi

desert · water · geology

Desert river valleys. Wadis are special riverbeds found in deserts that stay dry most of the time but fill up with rushing water when heavy rain falls.

Flash flood channels. When rain comes to the desert, wadis transform into powerful rivers that flow fast and furious, then disappear again as the water soaks into the ground.

Sediment builders. As water slows down in a wadi, it drops sand and rocks, creating dams that can change where water flows during the next big storm.

Found in dry lands. Wadis start at the edges of desert mountains where water first begins to flow, then stretch across flat desert toward inland salt lakes and dry basins.

Some never dry up. Most wadis are empty, but a few special ones like Wadi Bani Khalid have water flowing through them all year round.